U.S. patent number 5,166,011 [Application Number 07/609,770] was granted by the patent office on 1992-11-24 for process for forming an argentic oxide containing bipolar electrode and product produced thereby and deferred actuated battery assembly employing same.
This patent grant is currently assigned to Alupower, Inc.. Invention is credited to William Kobasz, Bhaskara M. L. Rao.
United States Patent |
5,166,011 |
Rao , et al. |
November 24, 1992 |
Process for forming an argentic oxide containing bipolar electrode
and product produced thereby and deferred actuated battery assembly
employing same
Abstract
There is disclosed a process for laminating a metal-based anode
member to one side of a conductive intermediate layer and an
argentic oxide-containing layer to the other side thereof and using
a plurality of such bipolar electrodes in a battery assembly
defining a compartment for passage of an alkaline medium, such as
seawater, or alkali.
Inventors: |
Rao; Bhaskara M. L.
(Flemington, NJ), Kobasz; William (Edison, NJ) |
Assignee: |
Alupower, Inc. (Warren,
NJ)
|
Family
ID: |
24442252 |
Appl.
No.: |
07/609,770 |
Filed: |
November 7, 1990 |
Current U.S.
Class: |
429/219; 429/152;
429/210; 429/218.1; 429/231.6; 429/245 |
Current CPC
Class: |
H01M
4/06 (20130101); H01M 4/624 (20130101); H01M
4/661 (20130101); H01M 4/668 (20130101); H01M
6/34 (20130101); H01M 4/625 (20130101) |
Current International
Class: |
H01M
4/62 (20060101); H01M 4/66 (20060101); H01M
4/06 (20060101); H01M 6/34 (20060101); H01M
6/30 (20060101); H01M 004/34 (); H01M 004/54 ();
H01M 006/48 () |
Field of
Search: |
;429/210,219,218,152,245 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Bell; Mark L.
Attorney, Agent or Firm: Marn; Louis E.
Claims
What is claimed is:
1. A bipolar electrochemical electrode which comprises:
an inert intermediate conductive layer;
an electronegative member laminated to a side of said intermediate
conductive layer and formed of a material selected from the group
consisting of aluminum, aluminum alloys, magnesium, magnesium
alloys and mixtures thereof; and
an argentic oxide-containing electropositive layer laminated to
another side of said inert intermediate conductive layer.
2. The bipolar electrochemical electrode as defined in claim 1
wherein said inert intermediate conductive layer is of a thickness
of from 1 to 0.05 mils.
3. The bipolar electrochemical electrode as defined in claim 2
wherein said inert intermediate conductive layer is a carbon
particle containing plastic and a material selected from the group
consisting of carbon fibers, graphite fibers, nickel plated carbon
fibers, nickel plated graphite fibers, silver plated carbon fibers,
silver plated graphite fibers, silver fine wire, silver flakes,
nickel fine wire, nickel flakes, nickel plated chopped fiber glass,
silver plated chopped fiber glass or mixtures thereof.
4. The bipolar electrochemical electrode as defined in claim 1, 2
or 3 wherein said argentic oxide-containing electropositive layer
includes a material selected from the group consisting of carbon
fibers, graphite fibers, nickel plated carbon fibers, nickel plated
graphite fibers, silver plated carbon fibers, silver plated
graphite fibers, silver fine wire, silver flakes, nickel fine wire,
nickel flakes, nickel plated chopped fiber glass, silver plated
chopped fiber glass or mixtures thereof.
5. The electrochemical electrode as defined in claim 4 wherein said
argentic oxide-containing electropositive layer includes a
binder.
6. The electrochemical electrode as defined in claim 5 wherein said
argentic oxide-containing electropositive layer contains less than
about 20% percent by weight water.
7. A process for manufacturing an argentic oxide-containing bipolar
electrode, which comprises:
a) laminating an electronegative member of a material selected from
the group consisting of aluminum, aluminum alloys, magnesium,
magnesium alloys and mixtures thereof to a side of an inert
intermediate conductive layer; and
b) laminating an electropositive member including argentic oxide to
another side of said inert intermediate conductive layer.
8. The process for manufacturing an argentic oxide-containing
bipolar electrode as defined in claim 7 wherein said
electropositive member is formed by admixing powdered argentic
oxide in an aqueous medium with a material selected from the group
consisting of carbon fibers, graphite fibers, nickel plated carbon
fibers, nickel plated graphite fibers, silver plated carbon fibers,
silver plated graphite fibers, silver fine wire, silver flakes,
nickel fine wire, nickel flakes, nickel plated chopped fiber glass,
silver plated chopped fiber glass or mixtures thereof forming said
admixture into a layer and drying said thus formed layer to form
said electropositive member.
9. The process for manufacturing an argentic oxide-containing
bipolar electrode as defined in claim 8 and further including a
binder medium in said admixture.
10. The process for manufacturing an argentic oxide-containing
bipolar electrode as defined in claim 9 wherein said binder is an
aqueous Teflon.RTM. emulsion.
11. The process for manufacturing an argentic oxide-containing
bipolar electrode as defined in claim 7 wherein said argentic oxide
is formed by oxidizing argentous oxide in silver.
12. The process for manufacturing an argentic oxide-containing
bipolar electrode as defined in claim 8 wherein drying is effected
to a water content of less than 20% percent by weight.
13. An electrochemical battery assembly which comprises:
an anode plate formed of a material selected from the group
consisting of aluminum, aluminum alloys, magnesium, magnesium
alloys and mixtures thereof;
an inert cathode current collector plate; and
a plurality of bipolar electrochemical electrodes disposed between
said anode plate and said inert cathode current collector plate,
said bipolar electrochemical electrodes comprises of an inert
intermediate conductive layer; an electronegative member laminated
to a side of said intermediate conductive layer and formed of a
material selected from the group consisting of aluminum, aluminum
alloys, magnesium, magnesium alloys and mixtures thereof; and an
argentic oxide-containing electropositive layer laminated to
another side of said inert intermediate conductive layer.
14. The electrochemical electrodes", and substitute electrochemical
battery assembly; and as defined in claim 13 wherein said inert
intermediate conductive layer is of a thickness of from 1 to 0.05
mils.
15. The electrochemical electrodes", and substitute electrochemical
battery assembly; and as defined in claim 14 wherein said inert
intermediate conductive layer is a carbon particle containing
plastic and a material selected from the group consisting of carbon
fibers, graphite fibers, nickel plated carbon fibers, nickel plated
graphite fibers, silver plated carbon fibers, silver plated
graphite fibers, silver fine wire, silver flakes, nickel fine wire,
nickel flakes, nickel plated chopped fiber glass, silver plated
chopped fiber glass or mixtures thereof.
16. The electrochemical electrodes", and substitute electrochemical
battery assembly; and as defined in claim 12, 13, or 14 wherein
said argentic oxide-containing electropositive layer includes a
material selected from the group consisting of carbon fibers,
graphite fibers, nickel plated carbon fibers, nickel plated
graphite fibers, silver plated carbon fibers, silver plated
graphite fibers, silver fine wire, silver flakes, nickel fine wire,
nickel flakes, nickel plated chopped fiber glass, silver plated
chopped fiber glass or mixtures thereof.
17. The electrochemical battery assembly as defined in claim 16
wherein said argentic oxide-containing electropositive layer
includes a binder.
18. The electrochemical battery assembly as defined in claim 17
wherein said argentic oxide-containing electropositive layer
contains less than about 20% percent by weight water.
Description
BACKGROUND OF THE INVENTION
1) Field of the Invention
This invention relates to electrochemical batteries, and more
particularly to an improved argentic oxide bipolar electrode for
use in an electrochemical battery for marine use of improved
reliability.
(2) Description of the Prior Art
Battery requirements for marine data systems vary from a few
milliwatts for CMOS instrumentation to several tens of kilowatts
for the operation of a mini autonomous underwater vehicle (AUv).
Nonaqueous lithium cells and zinc-based primary cells, as well as
nickel-cadmium and lead-acid batteries, are currently used. Safety
and the corrosive nature of the electrolyte and/or some cathode
materials used in such power sources dictate that cells and
batteries be well sealed to prevent leakage and/or rupture during
storage and use. Lithium batteries use hermetic seals with safety
vents and a fuse. Alkaline cells are rendered leakproof by suitable
double crimp joints. Lead-acid cells use a gelled electrolyte to
prevent spillage of the electrolyte. Such techniques have minimized
the hazards of handling and use, however at the expense of the
costs. Sealed cells require a "pressure hull" enclosure for deep
sea application and thus use of a pressure hull significantly
reduces energy density and concomitantly increases usage cost.
Other types of power cells used in undersea applications are water
activated magnesium batteries with a bipolar configuration as open
cells. A magnesium anode and a metal halide-based cathode allows
the use of sea water as the electrolyte and do not require a
pressure hull housing for deep sea applications.
Deferred actuated batteries, such as silver chloride-magnesium
batteries using sea water as an electrolyte have been used for
years, and are expensive being based upon the use of a precious
metal, i.e. silver.
Aluminum-silver oxide batteries for use in electric torpedoes
include bipolar electrodes formed of an aluminum alloy plate, a
silver foil and an electroformed silver oxide layer containing a
silver grid with silver in the argentous ionic form. Fabrication of
such bipolar electrode and assembly into a battery configuration is
cumbersome, costly and exceedingly unreliable due to the use of
tape to hold together the bipolar electrode. There are requirements
for high energy and high power density with concomitant depth
independency.
In U.S. Pat. No. 4,910,104 to Rao et al. and assigned to the same
assignee as the present invention, there is described a deferred
actuated battery assembly for seawater activation.
OBJECTS OF THE PRESENT INVENTION
An object of the present invention is to provide an improved
bipolar electrode assembly for an aluminum-silver oxide
battery.
Another object of the present invention is to provide an improved
bipolar electrode assembly for a deferred aluminum-silver oxide
battery for improved reliability.
Still another object of the present invention is to provide an
improved bipolar electrode assembly for an aluminum-silver oxide
battery of facile construction.
A still further object of the present invention is to provide an
improved bipolar electrode assembly for an aluminum-silver oxide
battery of reduced construction costs.
Yet another object of the present invention is to provide an
improved deferred actuated aluminum-silver oxide battery of
enhanced power density.
Still yet another object of the present invention is to provide an
improved bipolar electrode assembly for an aluminum-silver oxide
battery of depth independency.
SUMMARY OF THE INVENTION
These and other objects of the present invention are achieved by
laminating a metal-based anode member to one side of a conductive
intermediate layer and an argentic oxide-containing layer to the
other side and using a plurality of such bipolar electrodes in a
battery assembly defining a compartment for passage of an alkaline
medium, such as seawater, or alkali .
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and advantages of the present invention will become
apparent from the following detailed description when taken with
the accompanying drawing, wherein:
FIG. 1 is a cross-sectional view of the improved aluminum-argentic
oxide bipolar electrode of the present invention;
FIG. 2 is a schematic cross-sectional view of a battery assembly
illustrating a flow through type configuration; and
FIG. 3 is a discharge curve for an Al/AgO bipolar electrode
prepared from chemically-formed argentic oxide in an aqueous
solution of potassium hydroxide (4 m KOH).
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings and particularly FIG. 1, there is
schematically illustrated an integral bipolar electrode of the
present invention, generally indicated as 10 including a
metal-based anode member 12, an intermediate inert conductive
member 14 and a cathode member 16. The metal-based negative
electrode or anode member 12 is formed of a material selected from
the group consisting of aluminum, aluminum alloy, magnesium,
magnesium alloy and mixtures thereof of a thickness of from 2 mils
to one inch, as a function of capacity.
The conductive inert intermediate member or layer 14 is comprised
of carbon particle-containing plastic nickel, copper or silver foil
of a thickness of from 1 to 0.05 mils. The conductive inert
intermediate member or layer 14 is laminated to the aluminum anode
member 12 by thermal/pressure bonding, preferably using conductive
adhesive or solvent bonding techniques under conditions to maintain
a low interfacial resistance to permit of large currents across the
bipolar boundary. Thus, for example, with a resistance junction,
the resultant 1R-loss would be 10 mv at 1A/cm2 discharge.
The positive electrode or cathode member or layer 16 is laminated
by heat to the other side of the conductive inert intermediate
layer 14. The positive electrode 14 is formed by admixing
chemically-formed powdered argentic oxide with a material selected
from the group consisting of carbon fibers, graphite fibers, nickel
plated carbon fibers, nickel plated graphite fibers, silver plated
carbon fibers, silver plated graphite fibers, silver fine wire,
silver flakes, nickel fine wire, nickel flakes, nickel plated
chopped fiber glass, silver plated chopped fiber glass or mixtures
thereof, in a suitable binder medium. The binder medium includes
e.g. aqueous polytetre fluoro ethylene emulsions, i.e. Teflon.RTM.
or polyvinyl chloride. The admixture is formed into a paste and is
spread to an even thickness on a release substrate and subsequently
dried to remove excess water, preferably less than about 20%
percent by weight water.
Silver Oxide (Ag.sub.2 O) is the stable in positive form of the
argentous ion, Ag.sup.+. however, in the present invention, the
argentous ion may be oxidized to the argentic form (Ag++) which may
be effected by using strong oxidizing agents, such as sodium
potassium per oxy disulfate with concomitant adjustment of pH and
temperature, it being understood that silver ion is present in a
combined +1, +2 or +3 state or a form of Ag.sub.x O wherein x is
less than 2. Other forms of chemically or electrochemically-formed
argentic oxide can be used in the present invention.
A plurality of bipolar electrodes 10 of the present invention,
referring now to FIG. 2, are disposed in a battery assembly;
generally indicated as 20, between an anode plate 22 and an inert
cathode current collector plate 24 encased by a dielectric material
26, such as any conventional plastic material suitable for battery
usage. Generally, spacing being adjacent bipolar electrodes 10 is
not greater than about 0.5 inches to provide an adequacy
internally-connected semi configuration. There being no top or
bottom wall member, the battery assembly 20 permits the
introduction as well as flow through of the alkaline electrolyte,
such as seawater or alkali or a mixture thereof.
The anode plate 22 is likewise formed of a material selected from
the group consisting of aluminum, aluminum alloys, magnesium,
magnesium alloys and mixtures thereof with a thickness being a
function of capacity as hereinabove discussed with reference to the
electronegative member 12. The inert cathode current collector
plate 24 is formed of an inert conducting substrate, such as
nickel, carbon, silver, lead and the like.
EXAMPLE OF THE INVENTION
Operation of the process and apparatus is described in the
following specific example which are intended to be merely
illustrative and the present invention is not to be regarded as
limited thereto.
EXAMPLE I
Sixteen grams of argentic oxide (AgO) is admixed with 12 grams
water and 1.2 grams Teflon.RTM. to form a paste spread lengthwise
onto a Teflon.RTM. coated release paper. After removal of excess
water, the layer is dried at 45.degree. C. and pressed onto a
silver foil side of an aluminum/silver laminate to form a bipolar
electrode.
The discharge curves of FIG. 3 illustrate the high rate and high
efficiency of silver oxide utilization and efficacy of the improved
metal-based argentic oxide bipolar electrode of the present
invention.
While the invention has been described in connection with an
exemplary embodiment thereof, it will be understood that many
modifications will be apparent to those of ordinary skill in the
art; and that this application is intended to cover any adaptations
of variations thereof. Therefore, it is manifestly intended that
this invention be only limited by the claims and the equivalents
thereof.
* * * * *